Few days ago I decided to continue my interactive robot (https://www.robotshop.com/letsmakerobots/node/36100), and it's been some time I'm making some sketches for a more interactive head for this project, since the other (dome head) is limited to a ultrasonic sensor.
I made this "Something Else" post because this head probably will be used in others projects too. Or maybe I'll start a new project, since this head don't combine with the round body of MDi-eins. I'm thinking about...
Well, yesterday I made a cardboard prototype and I put on it pan and tilt servos to test effectively how it looks.
Below is a SketchUp drawing and after the cardboard prototype.
To make these red eyes I utilized just two 8x8 dot led matrix, two MAX7219 IC, four capacitors, two resistors and many many wires. When I'll make the final head with polystyrene, I'll make too a small PCB with the ICs and put it inside of the head, which will eliminate the mess of wires.
Wowwwww!!! What a mess!!! Yes I know that cannot understand anything on this... but, believe me, it really works!!! :)
As I found on the web some good material about utilizing led matrix with MAX7219, I won't make here a tutorial, because it would just copying what other people already made. But I leave here some links where I found everything (library, example code and schematic).
http://tronixstuff.wordpress.com/2010/07/09/review-maxim-max7219-led-display-driver-ic/
http://www.wayoda.org/arduino/ledcontrol/index.html
http://tomekness.files.wordpress.com/2008/01/max7219_tutorial_pre_c.pdf (this last one is a tutorial in PDF)
The final head will have a sensor at the bottom (I'm thinking between a HC-SR04 and Sharp IR). Also it will have small speakers at the left and right sides, as seen on the sketch.
I'm working in other expressions like anger, sadness, happiness, fear and scare, for example, when it's running around autonomously and suddenly appear an obstacle on his front.
UPDATE - June 8, 2013
Hi guys. Just a little update.
I have worked in some new expressions. I was thinking about the ideas of OddBot and AdamONE, but I ended up keeping the eyes in a simple shape, changing a little bit of them, since my matrix have only 64 dot (x2), compared with the Eve's eyes (which must have 1000 dots, I think), and which in my case (with a few leds) makes the shapes a bit squared.
I have painted in black the background of eyes (I think it looks better now).
Just added another video with the new expressions in a simple sequence of: NEUTRAL - SADNESS - SURPRISE - HAPPINESS - FEAR - FLAT EYES BLINKING - HORIZONTAL & VERTICAL SEEKING.
Below are some pics of the five expressions that I made for this moment (maybe need some adjusts). My prefered is the "SADNESS".
I would like to provide here the code files, but I think it's not possible in "Something Else" posts. So, below I show a short code:
#include "LedControl.h"
LedControl lc=LedControl(12,11,10,2);
void setup()
{
lc.shutdown(0,false);
lc.setIntensity(0,1);
lc.clearDisplay(0);
lc.shutdown(1,false);
lc.setIntensity(1,1);
lc.clearDisplay(1);
}
void loop()
{
neutral();
}
void neutral()
{
lc.setRow(0,0,60);
lc.setRow(0,1,126);
lc.setRow(0,2,102);
lc.setRow(0,3,102);
lc.setRow(0,4,102);
lc.setRow(0,5,126);
lc.setRow(0,6,60);
lc.setRow(1,1,60);
lc.setRow(1,2,126);
lc.setRow(1,3,102);
lc.setRow(1,4,102);
lc.setRow(1,5,102);
lc.setRow(1,6,126);
lc.setRow(1,7,60);
delay(50);
}